iOS UIView转UIImage与CALayer转UIImage的差异

UIView转UIImage

- (UIImage *)snapshotImage {
    UIGraphicsBeginImageContextWithOptions(self.bounds.size, self.opaque, 0);
    [self.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

效果：有黑底

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CALayer转UIImage

- (UIImage *)snapshotImage {
    UIGraphicsBeginImageContextWithOptions(self.bounds.size, self.opaque, 0);
    [self renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

效果：没黑底

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一行代码生成渐变色

https://github.com/xjh093/JHDraw

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